Abstract

A three year study of the seasonal changes in the biodiversity and the density of the waterfowl and wader were carried out in Sorkhrud International Wetland which is a part of Feridonkenar's intentional wetlands (registered in Ramsar Convention). Birds were counted through the total count method. The study included 119592, 140901 and 139160 waterfowl and waders were counted in the winter of 2007, 2008 and 2009 respectively. The average density of species in this wetland varied from 64 to 76 birds in a ha. In all of the mentioned years, maximum density started with waterfowl and continued by waders in one month period respectively. Common Teal (Anas crecca), White-fronted Goose (Anser anser)and Mallard (Anas platyrhynchos) were the dominant species in almost all years. Overwintering birds formed the major population of the migratory birds of the area. On the average, Sorkhrud International Wetland had hosted 21 species, 133217 birds, a species richness of 0.22 and 1.14 for Menhinick and Margalef respectively, a species diversity of 0.68 for Simpson, 0.7307 for Pauly and 1.66 for Shannon-Wiener.

Key words: Sorkhrud international wetland, waterfowl and waders, biodiversity indices.